Adjustable support for swinging lamps



(No Model.) i 2 sheets-sheen 1. L. F. JORDAN.

ADJUSTABLBSUPPORT POR SWINGING LAMPS.

(No Model.) 2 Sheets-Sheet 2.

L. P. JORDAN.

ADJUSTABLE SUPPORT POB. SWINGING LAMPS.

No. 416,368. Patented Dec. 3, 1889.

N. PETERS, Pham-Uthunpmr. Washmgion. DA c UNITED STATES PATENT OFFICE.

LINVOOD F. JORDAN, OF SOMERVILLE, MASSACHUSETTS.

ADJUSTABLEl SUPPORT FOR SWINGING LAMPS.

SPECIFICATION forming part of Letters Patent No..416,368, dated December 3, 1889.

Application filed May 1l, 1889. Serial No. 310,443. (No model.)

To @ZZ whom it may concern:

Be it known that I, LINwooD F. JORDAN, a citizen of the United States, residing at Somerville, county of Middlesex, and State of Massachusetts, have invented certain new and useful Improvements in Adjustable Supports for Swinging Lamps, of which the following is a specification.

This invention relates to adjustable lampsupports adapted to suspend a lamp at a considerable height and at a distance from the street, and at the same time capable of being lowered to within convenient reach 'of a workman for necessary attention.

The invention consists in the novel structure and combination of parts fully hereinafter set forth.

In the drawings, Figure l is a side elevation of the improved support. Fig. 2 is a like view looking from the right of Fig. l. Fig. 3 is a plan view of the same. Fig. 4 is an end view of the yard-arm, showing the lamp in position. Fig. 5 is avertical section taken through the cap-piece. Fig. 6 is a side elevation'of a modified form of the manner of adjusting the yard-arm, and Fig. 7 is a sectional detail on the line 7 7 of Fig. 6. n

In said drawings, which illustrate one form of the adjustable support, A represents the mast, B the yard-arm, and C the lamp suspended at the end of the yard-arm. The mast in the preferred construction consists of a base portion 2O and an upper portion 2l of duplex form, consisting, as shown, of `two columns 22, rising vertically from the-base portion and united together at their upper ends by a cappiece 23, which supports the pivot 24 for the yard-arm. The yard-arm B is of skeleton form, made up of bearing-pieces 25 for the pivot 24, end bar 26, connecting side bars 27, and extension-bars 2S, united together by an end piece 29, and affording seats for counterbalancing-weights 30. The yard-arm may be strengthened by a truss 3l, if desired. In practice it is necessary to provide such structures with means for conveniently raising and lowering the end of the yard-arm and for adjusting and holding it in its adjusted position. This is particularly requisite when the lamp suspended at the end of the yard-arm is an electric arc lamp, which, as is well known, requires the renewal of carbons each day. This adjustment of the yard-arm is` effected in the present case by rigidly securing the pivot 24 to the bearing-pieces 25,`so that turning said pivot in either direction will impart a like movement to the arm B. To impart this movement to the yard-arm, there is provided, Figs. l and 5, a sprocket-wheel 32, keyed or otherwise secured to the pivot 24, with which sprocket-wheel an endless chain 33 engages, extending down within easy reach of a workman. Said chain may be moved by means of a second sprocket-wheel 34, mounted in the mast near its lower end, having a crank 35 for rotating it.

In order to remove the sprocket-wheel and chain from exposure .to the weather, I prefer to inclose them within the mast. For this purpose, as well as to lighten the structure materially, the mast is formed of hollow metal. Thus the columns 22 are tubular, secured at their lower ends in a hollow casing 36, fast upon the face portion 20, which latter may or may not be hollow, as is desired. The hollow casing 36 may be formed for convenience in casting of two portions and bolted together and forming a suitable housing for the sprocket-wheel 34, as well as affording bearings for the lower crank-shaft, to which it is keyed. The upper ends 'of the tubular columns are secured in the cap-piece 23, which is also hollow, and may be formed of two portions bolted together and forming a housing for the upper sprocket-wheel 3,2, the construction being such that the endless chain passing around the sprocket-wheels will pass up and down through the tubular columns, one length passing through one column and the other length through the other column. Thus each length of the chain is protected independently of the other.

From the foregoing it will be seen that as the yard-arm is fast to the shaft of the upper sprocket-wheel any movement imparted to the chain through the lower sprocket-wheel will impart a corresponding movement to said yard-arm and cause it to be raised or lowered at will.

As shown in Figs. 6 and 7, the sprocketwheel 32, instead of being 'mounted on the pivot 24, is secured to a shaft 124, having on IOO its outer end a pinion 133, meshing with'a quadrant-rack 134-, carried by the yardarm. The operation of raising and lowering the yard-arm will be substantially the same as that before described, the motion communicated by the chain to the sprocket-wheel 32 rotating the pinion and causing the yard-arm t0 be vibrated from a horizontal position downward or from a lowered position upward.

The lamp C, in the illustrations shown as an electric-arc lamp, is provided with the usual reiiector and guard 37, and is loosely hung from the end bar E26 of the yard-arm by links 3S, that are secured to the usual lampframe. The length of the links will be such as `to permit the upper projecting end of the lampthe reiiector in this case--to readily swing under the end bar 26 without danger of striking it. This feature is to allow the lamp tohang perfectly straight, no matter what may be the position of the yardarm with respect to the mast.

The electric conductors i() are each led to and secured rst to an insulator 41, mounted on the end of the pivot-shaft 24, and from thence to an insulator f 2, fast on the end of the end bar 2G, and thence to the bindingposts of the lamp.

A convenient mode of sustaining the truss 31 is to provide an arched brace 43, secured to the pivot-shaft 2t just outside the cappiece 23, as shown in Fig. 5. The vertical columns 22 of the mast lmay also be provided with the trusses 14, sustained by a brace-bar 15, seated against the columns and passing between them to brace both of the trusses.

The yard-arm may be secured in its adjusted position by any suitable means. Thus the crank 35 may be locked to the side of the mast, and for this purpose the handle portion 9 may be pivoted to the crank and adapted to be swung to the opposite side thereoi.` to lit in a socket 8 and secured therein by a hasp cured to its upper end, a sprocket-wheel at the upper end of the mast adapted to operate the yard-arm, and a chain engaging with thc wheel and extending to the lower portion of the mast, substantially as described.

2. In an adjustable lanlp-supl'iort, the combination, with a mast consisting of a pair of tubular columns and a hollow cap-piece, of a yard-arm pivoially secured at the top of the mast, a sprocket-wheel in the cap adapted to operate the yard-arm, another sprocket-wheel near the lower end of the mast, and an endless chain over said wheels and within the columns, substantially as described.

4. In an adjustable lamp-support,tl1e combination, with agnast consisting of a basepiece, a cap-piece, and two tubular columns secured at their ends in the base and cap piece, of a yard-arm pivotally secured to the top of the mast, a sprocket-wheel in the cap-piece adapted to operate the yard-arm, a sprocketwheel in the base-piece, and an endless chain wit-hin the two columns and around the sprocket-wheels, substantially as described.

5. In an adj ustable lamp-support, the coln bination of a mast, pivots journaled in the upper portion of the mast, a yard-arm, a sp1ocl:etwheel rigidly secured to the pivot, and a chain for operating the wheel, substantially as described.

6. In an adjustable lamp-support, the coinbination of the mast consisting of a base portion, a hollow casing having bearings for a crank-shaft, a pair of tubular columns, and a hollow cap-piece having bcarin gs for a pivotal shaft, all secured together, an endless chain connecting the two shafts, and a yard-arm pivotally mounted to the top piece of the mast, substantially as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

LINW'OOD F. JORDAN.

Witnesses:

OREN S. KNAPP, THOMAS M. SHAW, Jr. 

